A process for preparing a ball clay slurry comprised of water, ball clay, and a dispersing agent.
U.S. Pat. No. 4,812,427 describes a ball clay/water slurry that contains organic polyelectrolyte. This slurry, which is sold under the name of xe2x80x9cFLO-TECHxe2x80x9d by the H. C. Spinks Clay Company of Paris, Tenn., has met with a substantial amount of commercial success.
Example 4 of U.S. Pat. No. 4,812,427 describes a typical xe2x80x9cFLO-TECHxe2x80x9d slurry which, according to the patent, had a transmission of 76 percent. For some end uses, a slurry with a higher transmission value is desired.
It is an object of this invention to provide a process for preparing a ball clay/slurry with a transmission greater than 90 percent, a casting rate in excess of 50, and a modulus of rupture in excess of 500 pounds per square inch.
In accordance with this invention, there is provided a process for preparing a ball clay slurry with a casting rate of at least about 50, a modulus of rupture of at least 500 pounds per square inch, and from about 0.1 to about 1.0 weight percent of organic polyelectrolyte. In this process, a digested lignite material is mixed with a lignitic coarse clay, a nonlignitic coarse clay, a lignitic fine clay, and a polyelectrolyte dispersing agent.